Currently, to form a photo-mask for preparing a lead frame or an encoder, silver halide light sensitive photographic materials are subjected to exposure, with a plotter using a laser light source, and processed. Pattern images of the mask have become finer over the years and along therewith, the diameter of the laser light spot has also become smaller, and thereby image exposure is performed with rapid scanning. A decrease of the diameter of a laser light beam results in increased convergence of the laser so that the photographic material is exposed to laser with higher intensity and for a shorter period of time. As a result, deterioration of image sharpness, due to light scattering on the surface of the photographic material, becomes serious along with the increase of finer patterns. With regard to photographic materials, therefore, a technique is desired, in which fine patterns can be sharply reproduced even when subjected to high intensity, short-time exposure, such as laser exposure.
Glass dry plates for use in laser exposure have been conventionally processed mainly with a lith developer containing only hydroquinone as a developing agent. An advantage of the use of the lith developer is that edges of a line image are sharp and an image with ultra-high contrast can be obtained. On the other hand, the lith developer is notoriously unstable so that the level of the developer must be precisely controlled during processing. Thus, when a number of the dry plates are processed, there occur fluctuations of the line image width or the image density due to variation of developer stirring or developer activity. In light of the foregoing, a processing method is being studied, in which glass dry plates are processed with a rapid-access developer which is stable, compared to conventional lith developers and contains two or more developing agents.
When a dry plate which was conventionally processed with a lith developer was processed with the rapid-access developer, a number of fringes were disadvantageously produced at edge portions and superior images could not be obtained. To improve such defective image quality, JP-A 8-254796 discloses a technique of incorporating a hydrazine compound into a photographic material and JP-A 7-146523 discloses incorporation of a tetrazolium compound to obtain images with reduced fringes (herein, the term, "JP-A" means an unexamined and published Japanese Patent Application). The former is to accelerate development in the vicinity of images to obtain a high contrast image. In this case, however, the following defect was exhibited that, if a development center is present in an unexposed white background, it is developed to form a circular black spot, which becomes a foreign material in the mask. In the latter case, although no black foreign material is actually produced, there were defects exhibited such that the mask was discolored with by-products of the tetrazolium salt produced during development and was easily varied with preparation conditions, and further batch variation was large with respect to sensitivity.